DNA porcine viruses detected on fresh liver samples destined for human consumption

Pork meat and pork-derived products are major sources of protein, but they might be important vehicles for transmitting viruses to humans. Here we aimed to evaluate whether pig enzootic viruses could be found in liver samples destined for foodstuff manufacture. We collected 140 liver samples in a slaughterhouse for DNA extraction and viral detection by real-time or conventional PCR. The samples were from 14 swine herds (n = 10/herd) located in Rio Grande do Sul state, Brazil. We found 93 (66.4%) samples positive for swine torque teno virus (TTSuV); out of these, 29 samples (31.2%) were positive for TTSuV1, 39 (41.9%) for TTSuV2 and 25 (26.9%) for both TTSuV genotypes. Porcine circovirus type 2 (PCV2) DNA was found on 24 (17.1%) samples, out of which 23 were PCV2d and only one was PCV2b. Half of the samples from each farm were tested for adenoviruses (AdV) and 44 (62.8%) were positive: by analyzing the melting curve, the samples were classified as adenoviruses of human (HAdV), canine (CAdV), and bird (AVAdV) origin in 39 (55.7%), 11 (15.7%) and 3 (4.2%) of the samples. Porcine parvovirus (PPV) DNA was detected in 5 (7.1%) of the 70 samples analyzed. Pork liver is commonly used for making pate, sausages, and mortadella which, in this situation, could harbor these viruses. Further processing of foodstuff is likely to inactive viral agents; however, our data indicates that pork-derived meat might contain viruses that eventually could reach the food chain and be harmful to immunocompromised individuals.